Development and Validation of an Arterial Pressure-Based Cardiac Output Algorithm Using a Convolutional Neural Network: Retrospective Study Based on Prospective Registry Data.

BACKGROUND: Arterial pressure-based cardiac output (APCO) is a less invasive method for estimating cardiac output without concerns about complications from the pulmonary artery catheter (PAC). However, inaccuracies of currently available APCO devices have been reported. Improvements to the algorithm by researchers are impossible, as only a subset of the algorithm has been released. OBJECTIVE: In this study, an open-source algorithm was developed and validated using a convolutional neural network and a transfer learning technique. METHODS: A retrospective study was performed using data from a prospective cohort registry of intraoperative bio-signal data from a university hospital. The convolutional neural network model was trained using the arterial pressure waveform as input and the stroke volume (SV) value as the output. The model parameters were pretrained using the SV values from a commercial APCO device (Vigileo or EV1000 with the FloTrac algorithm) and adjusted with a transfer learning technique using SV values from the PAC. The performance of the model was evaluated using absolute error for the PAC on the testing dataset from separate periods. Finally, we compared the performance of the deep learning model and the FloTrac with the SV values from the PAC. RESULTS: A total of 2057 surgical cases (1958 training and 99 testing cases) were used in the registry. In the deep learning model, the absolute errors of SV were 14.5 (SD 13.4) mL (10.2 [SD 8.4] mL in cardiac surgery and 17.4 [SD 15.3] mL in liver transplantation). Compared with FloTrac, the absolute errors of the deep learning model were significantly smaller (16.5 [SD 15.4] and 18.3 [SD 15.1], P<.001). CONCLUSIONS: The deep learning-based APCO algorithm showed better performance than the commercial APCO device. Further improvement of the algorithm developed in this study may be helpful for estimating cardiac output accurately in clinical practice and optimizing high-risk patient care.

Effect of Fentanyl-Based Intravenous Patient-Controlled Analgesia with and without Basal Infusion on Postoperative Opioid Consumption and Opioid-Related Side Effects: A Retrospective Cohort Study.

PURPOSE: We aimed to investigate the effect of a basal opioid infusion in fentanyl-based intravenous patient-controlled analgesia (IV-PCA) on postoperative opioid consumption, pain intensity, and occurrence of opioid-related side effects. PATIENTS AND METHODS: We retrospectively reviewed 2097 consecutive patients who received IV-PCA after elective general, thoracic, urologic, and plastic surgery under general anesthesia between June 2019 and October 2019. The patients were divided into two groups: IV-PCA with basal infusion (basal group) and IV-PCA without basal infusion (no basal group). We performed a propensity score matching (PSM) analysis to adjust for baseline differences between both groups. We compared the fentanyl PCA consumption (mcg), pain intensity, rescue analgesic administration, and occurrence of opioid-related side effects (nausea, vomiting, somnolence or dizziness, and overall side effects) during the first 48 hours postoperatively between the two groups before and after PSM. RESULTS: We analyzed 1317 eligible patients. Of these, 757 (57.5%) patients received IV-PCA without basal infusion. The PSM of the total cohort yielded 539 pairs of cases. After PSM, the fentanyl PCA consumption was significantly lower in the no basal group at 48 hours postoperatively as compared to the basal group (at 24 hours, the median difference: -80 mcg, P<0.001, 95% CI=-112 - -45 mcg; at 48 hours, the median difference: -286 mcg, P<0.001, 95% CI=-380 - -190 mcg), without significantly increasing pain intensity and administration of rescue analgesia. The occurrence of overall opioid-related side effects was also significantly lower in the no basal group (at 24 hours: 31.0% vs 23.0%, OR=0.67, P=0.003, 95% CI=0.51 - 0.87; at 48 hours: 18.9% vs 11.0%, OR=0.48, P<0.001, 95% CI=0.31 - 0.75). CONCLUSION: Basal infusion of fentanyl-based IV-PCA was significantly associated with an increase in fentanyl consumption and the occurrence of opioid-related side effects in postsurgical patients.

The 'R' principles in laboratory animal experiments.

Since the Three Rs of replacement, reduction and refinement was proposed by Russel and Birch in 1959, researchers have a moral duty to minimize harm to animals. Even though animal experiments are performed by the Three Rs concept, animal researches which do not comply with international rules and standards are not accepted as well. As animal welfare has been important global issues, the methods to assess animal welfare compromise and distress have been proposed. Humanity is accepted as the goal of the Three Rs, however, another fourth R, 'Refusal' of fruitless protocol or 'Responsibility' for the experimental animal and social, scientific status of the animal experiments has been proposed. After establishing goals of animal research in a respective society, reliable knowledge can be obtained while improving laboratory animal welfare.

Intraoperative Oxygen Delivery and Acute Kidney Injury after Liver Transplantation.

Although intraoperative hemodynamic variables were reported to be associated with acute kidney injury (AKI) after liver transplantation, the time-dependent association between intraoperative oxygen delivery and AKI has not yet been evaluated. We reviewed 676 cases of liver transplantation. Oxygen delivery index (DO2I) was calculated at least ten times during surgery. AKI was defined according to the Kidney Disease Improving Global Outcomes criteria. The area under the curve (AUC) was calculated as below a DO2I of 300 (AUC < 300), 400 and 500 mL/min/m2 threshold. Also, the cumulative time below a DO2I of 300 (Time < 300), 400, and 500 mL/min/m2 were calculated. Multivariable logistic regression analysis was performed to evaluate whether AUC < 300 or time < 300 was independently associated with the risk of AKI. As a sensitivity analysis, propensity score matching analysis was performed between the two intraoperative mean DO2I groups using a cutoff of 500 ml/min/m2, and the incidence of AKI was compared between the groups. Multivariable analysis showed that AUC < 300 or time < 300 was an independent predictor of AKI (AUC < 300: odds ratio [OR] = 1.10, 95% confidence interval [CI] 1.06-1.13, time < 300: OR = 1.10, 95% CI 1.08-1.14). Propensity score matching yielded 192 pairs of low and high mean DO2I groups. The incidence of overall and stage 2 or 3 AKI was significantly higher in the lower DO2I group compared to the higher group (overall AKI: lower group, n = 64 (33.3%) vs. higher group, n = 106 (55.2%), P < 0.001). In conclusion, there was a significant time-dependent association between the intraoperative poor oxygen delivery <300 mL/min/m2 and the risk of AKI after liver transplantation. The intraoperative optimization of oxygen delivery may mitigate the risk of AKI.

Different Severity of Clinical Outcomes Between the 2 Subgroups of Stage 1 Acute Kidney Injury After Liver Transplantation.

BACKGROUND: Although the Kidney Disease: Improving Global Outcomes (KDIGO) criteria is used to define acute kidney injury (AKI) after liver transplantation, the criteria was criticized for including 2 heterogeneous groups of different serum creatinine (sCr) criteria together in AKI stage 1. We investigated whether there are significant differences in clinical outcomes between 2 subgroups of patients within AKI stage 1. METHODS: A total of 1440 cases were reviewed. The AKI stage 1 (n = 443) were divided into 2 subgroups based on changes in sCr level (stage 1a: ≥0.3 mg/dL of absolute sCr increase, n = 251; stage 1b: ≥50% relative sCr increase, n = 192). Propensity score analysis was performed between stage 1a and 1b groups, yielding 157 matched pairs. We compared the length of hospital stay, early allograft dysfunction, and 5-year all-cause mortality between these subgroups after matching. Kaplan-Meier analyses were performed to compare the graft or overall survival between the subgroups after matching. Sensitivity analysis for Acute Kidney Injury Network (AKIN) criteria was performed. RESULTS: Length of hospital stay and 5-year all-cause mortality was significantly worse in patients with stage 1b compared to stage 1a after matching. Five-year graft or patient survival was significantly worse in patients with stage 1b compared to stage 1a after matching (Log-rank test P = 0.022 and P = 0.027, respectively). These results were the same regarding AKIN criteria. CONCLUSIONS: The KDIGO criteria for AKI stage 1 could be further divided into 2 substages with different severity of clinical outcomes. This modified criteria could give additional prognostic information in patients undergoing liver transplantation.

Influence of Transfusion on the Risk of Acute Kidney Injury: ABO-Compatible versus ABO-Incompatible Liver Transplantation.

ABO-incompatible liver transplantation (ABO-i LT) is associated with a higher risk of acute kidney injury (AKI) compared to ABO-compatible liver transplantation (ABO-c LT). We compared the risk of AKI associated with transfusion between ABO-c and ABO-i living donor liver transplantation (LDLT). In 885 cases of LDLT, we used a propensity score analysis to match patients who underwent ABO-c (n = 766) and ABO-i (n = 119) LDLT. Baseline medical status, laboratory findings, and surgical- and anesthesia-related parameters were used as contributors for propensity score matching. AKI was defined according to the "Kidney Disease Improving Global Outcomes" criteria. After 1:2 propensity score matching, a conditional logistic regression analysis was performed to evaluate the relationship between the intraoperative transfusion of packed red blood cells (pRBCs) and fresh frozen plasma (FFP) on the risk of AKI. The incidence of AKI was higher in ABO-i LT than in ABO-c LT before and after matching (after matching, 65.8% in ABO-i vs 39.7% in ABO-c, p < 0.001). The incidence of AKI increased in direct proportion to the amount of transfusion, and this increase was more pronounced in ABO-i LT. The risk of pRBC transfusion for AKI was greater in ABO-i LT (multivariable adjusted odds ratio (OR) 1.32 per unit) than in ABO-c LT (OR 1.11 per unit). The risk of FFP transfusion was even greater in ABO-i LT (OR 1.44 per unit) than in ABO-c LT (OR 1.07 per unit). In conclusion, the association between transfusion and risk of AKI was stronger in patients with ABO-i LT than with ABO-c LT. Interventions to reduce perioperative transfusions may attenuate the risk of AKI in patients with ABO-i LT.

Intraoperative Hemodynamic Parameters and Acute Kidney Injury After Living Donor Liver Transplantation.

BACKGROUND: Acute kidney injury (AKI) after living donor liver transplantation (LDLT) is associated with increased mortality. We sought to identify associations between intraoperative hemodynamic variables and postoperative AKI. METHODS: We retrospectively reviewed 734 cases of LDLT. Intraoperative hemodynamic variables of systemic and pulmonary arterial pressure, central venous pressure (CVP), and pulmonary artery catheter-derived parameters including mixed venous oxygen saturation (SvO2), right ventricular end-diastolic volume (RVEDV), stroke volume, systemic vascular resistance, right ventricular ejection fraction, and stroke work index were collected. Propensity score matching analysis was performed between patients with (n = 265) and without (n = 265) postoperative AKI. Hemodynamic variables were compared between patients with AKI, defined by Kidney Disease Improving Global Outcomes criteria, and those without AKI in the matched sample. RESULTS: The incidence of AKI was 36.1% (265/734). Baseline CVP, baseline RVEDV, and SvO2 at 5 minutes before reperfusion were significantly different between patients with and without AKI in the matched sample of 265 pairs. Multivariable logistic regression analysis revealed that baseline CVP, baseline RVEDV, and SvO2 at 5 minutes before reperfusion were independent predictors of AKI (CVP per 5 cm H2O increase: odds ratio [OR], 1.20; 95% confidence interval [CI], 1.09-1.32; SvO2: OR, 1.45; 95% CI, 1.27-1.71; RVEDV: OR, 1.48; 95% CI, 1.24-1.78). CONCLUSIONS: The elevated baseline CVP, elevated baseline RVEDV after anesthesia induction, and decreased SvO2 during anhepatic phase were associated with postoperative AKI. Prospective trials are required to evaluate whether the optimization of these variables may decrease the risk of AKI after LDLT.

Intraoperative hyponatremia is an independent predictor of one-year mortality after liver transplantation.

Preoperative hyponatremia is associated with an increased risk of mortality on the liver transplantation (LT) waiting list. We sought to investigate the impact of pre- and intraoperative serum sodium levels on the one-year mortality after LT. We identified 1,164 patients for whom preoperative and intraoperative serum sodium levels were available. Cox regression analysis with multivariable adjustment was performed for one-year mortality. A propensity score matching analysis was performed for preoperative and intraoperative serum sodium groups to compare one-year survival. The cutoff of sodium level with minimal p-value was 130 mEq/L for both preoperative and intraoperative sodium. Intraoperative hyponatremia was an independent predictor of one-year mortality in the multivariable Cox regression analysis, while preoperative hyponatremia was not. Kaplan-Meier curve showed that there was a significant difference in the one-year mortality between preoperative and intraoperative serum sodium groups. However, after propensity score matching, there was no difference in the one-year mortality among the preoperative sodium groups, while there was a significant difference among the intraoperative sodium groups. Intraoperative hyponatremia defined by mean sodium <130 mEq/L was independently associated with a significantly high one-year mortality. Mean intraoperative serum sodium levels may be a better prognostic predictor than preoperative serum sodium levels.

Prediction of Acute Kidney Injury after Liver Transplantation: Machine Learning Approaches vs. Logistic Regression Model.

Acute kidney injury (AKI) after liver transplantation has been reported to be associated with increased mortality. Recently, machine learning approaches were reported to have better predictive ability than the classic statistical analysis. We compared the performance of machine learning approaches with that of logistic regression analysis to predict AKI after liver transplantation. We reviewed 1211 patients and preoperative and intraoperative anesthesia and surgery-related variables were obtained. The primary outcome was postoperative AKI defined by acute kidney injury network criteria. The following machine learning techniques were used: decision tree, random forest, gradient boosting machine, support vector machine, naïve Bayes, multilayer perceptron, and deep belief networks. These techniques were compared with logistic regression analysis regarding the area under the receiver-operating characteristic curve (AUROC). AKI developed in 365 patients (30.1%). The performance in terms of AUROC was best in gradient boosting machine among all analyses to predict AKI of all stages (0.90, 95% confidence interval [CI] 0.86⁻0.93) or stage 2 or 3 AKI. The AUROC of logistic regression analysis was 0.61 (95% CI 0.56⁻0.66). Decision tree and random forest techniques showed moderate performance (AUROC 0.86 and 0.85, respectively). The AUROC of support the vector machine, naïve Bayes, neural network, and deep belief network was smaller than that of the other models. In our comparison of seven machine learning approaches with logistic regression analysis, the gradient boosting machine showed the best performance with the highest AUROC. An internet-based risk estimator was developed based on our model of gradient boosting. However, prospective studies are required to validate our results.

Lower intra-abdominal pressure has no cardiopulmonary benefits during laparoscopic colorectal surgery: a double-blind, randomized controlled trial.

BACKGROUND: Higher intra-abdominal pressure may impair cardiopulmonary functions during laparoscopic surgery. While 12-15 mmHg is generally recommended as a standard pressure, the benefits of lower intra-abdominal pressure are unclear. We thus studied whether the low intra-abdominal pressure compared with the standard pressure improves cardiopulmonary dynamics during laparoscopic surgery. METHODS: Patients were randomized according to the intra-abdominal pressure and neuromuscular blocking levels during laparoscopic colorectal surgery: low pressure (8 mmHg) with deep-block (post-tetanic count 1-2), standard pressure (12 mmHg) with deep-block, and standard pressure with moderate-block (train-of-four count 1-2) groups. During the laparoscopic procedure, we recorded cardiopulmonary variables including cardiac index, pulmonary compliance, and surgical conditions. We also assessed postoperative pain intensity and recovery time of bowel movement. The primary outcome was the cardiac index 30 min after onset of laparoscopy. RESULTS: Patients were included in the low pressure with deep-block (n = 44), standard pressure with deep-block (n = 44), and standard pressure with moderate-block (n = 43) groups. The mean (SD) of cardiac index 30 min after laparoscopy was 2.7 (0.7), 2.7 (0.9), and 2.6 (1.0) L min-1 m-2 in each group (P = 0.715). The pulmonary compliance was higher but the surgical condition was poorer in the low intra-abdominal pressure than the standard pressure (both P < 0.001). Other variables were comparable between groups. CONCLUSION: We observed few cardiopulmonary benefits but poor surgical conditions in the low intra-abdominal pressure during laparoscopy. Considering cardiopulmonary dynamics and surgical conditions, the standard intra-abdominal pressure may be preferable to the low pressure for laparoscopic surgery.

Sevoflurane Postconditioning Reduces Apoptosis by Activating the JAK-STAT Pathway After Transient Global Cerebral Ischemia in Rats.

BACKGROUND: The antiapoptotic effects of sevoflurane postconditioning are responsible for neuroprotection against cerebral ischemia-reperfusion injury. Phosphorylation of the Janus family tyrosine kinases (JAK) 2-signal transducers and activators of transcription (STAT) 3 pathway is linked to antiapoptosis. Here, we determined whether the antiapoptotic effects of sevoflurane postconditioning are associated with activation of the JAK2-STAT3 pathway after global transient cerebral ischemia in rats. MATERIALS AND METHODS: Forty-five rats were randomly assigned to 5 groups: sham (n=5), control (10 min of ischemia, n=10), sevoflurane postconditioning (2 periods of sevoflurane inhalation after ischemia for 10 min, n=10), AG490 (a JAK2 selective inhibitor, intraperitoneal administration of 40 mg/kg before ischemia, n=10), and sevoflurane postconditioning plus AG490 group (n=10). The number of apoptotic cells as well as the expression of JAK2, phosphorylated JAK2 (P-JAK2), STAT3, phosphorylated STAT3 (P-STAT3), Bcl-2 (antiapoptotic protein), and Bax (proapoptotic protein) were evaluated 3 days after ischemia. RESULTS: The apoptotic cell count was significantly lower in the sevoflurane postconditioning group than in the control, AG490, and sevoflurane postconditioning plus AG490 groups. JAK2 and STAT3 levels were comparable among all 5 groups. P-JAK2, P-STAT3, and Bcl-2 levels were higher and Bax levels were lower in the sevoflurane postconditioning group relative to the control, AG490, and sevoflurane postconditioning plus AG490 groups. CONCLUSIONS: Sevoflurane postconditioning reduced apoptosis by increasing P-JAK and P-STAT expression after transient global ischemia in rats, and AG490 reversed the beneficial antiapoptotic effects of sevoflurane postconditioning, suggesting that the JAK-STAT pathway may be involved in the antiapoptotic mechanism of sevoflurane postconditioning.

Experience of hemostasis in tracheal bleeding very close to the carina by the bronchial blocker: a case report.

Massive hemoptysis is respiratory compromise which should be managed as a life-threatening condition. In our case, the bronchial blocker played a role in hemostasis of tracheal bleeding very close to the carina and prevented further spillage into the contralateral lung. Right-sided one-lung isolation in an 87-year-old female, who received cardiopulmonary resuscitation due to myocardial infarction, was requested due to hemoptysis. Right-sided bronchial bleeding was suspected on auscultation, but esophageal and tracheal bleeding due to violent intubation with a stylet was also considered. We attempted one-lung isolation with the bronchial blocker. The bronchial blocker was inadvertently advanced to the left mainstem bronchus, but the inflated balloon of the bronchial blocker compressed the site of bleeding, which was within 1 cm proximal and left posterior to the carina. Tracheal bleeding stopped, and we confirmed that hemostasis was achieved with the balloon of the bronchial blocker using a fiberoptic bronchoscope.

The State of Anesthetic Services in Korea: A National Survey of the Status of Anesthesia Provider in the 2011-2013 Period.

Active involvement of anesthesiologists in perioperative management is important to ensure the patients' safety. This study aimed to investigate the state of anesthetic services in Korea by identifying anesthetic service providers. From the insurance claims data of National Health Insurance for 3 yr, the Korean state of anesthetic services was analyzed. The claims for anesthesia from the medical institutions which hire their own anesthesiologist or with an anesthesiologist invitation fee are assumed to be the anesthesia performed by anesthesiologists. The annual anesthetic data were similar during the study period. In 2013, total counts of 2,129,871 were composed with general anesthesia (55%), regional anesthesia (36%) and procedural sedation with intravenous anesthetics (9%). About 80% of total cases of general anesthesia were performed in general hospitals, while more than 60% of the regional anesthesia and sedation were performed in the clinics and hospitals under 100 beds. Non-anesthesiologists performed 273,006 cases of anesthesia (13% of total) including 36,008 of general anesthesia, 143,134 of regional anesthesia, and 93,864 of sedation, mainly in the clinics and hospitals under 100 beds. All procedural sedations in the institutions without direct employed anesthesiologist were performed by non-anesthesiologists. Significant numbers of anesthesia are performed by non-anesthesiologist in Korea. To promote anesthetic services that prioritize the safety of patients, the standard to qualify anesthetic service is required. Surgeons and patients need to enhance their perception of anesthesia, and the payment system should be revised in a way that advocates anesthesiologist-performed anesthetic services.

Living donor liver transplantation for an infant with osteogenesis imperfecta and intrahepatic cholestasis: report of a case.

Osteogenesis imperfecta (OI) is a group of genetic disorders characterized by bone fragility and connective tissue manifestations. We report a successful liver transplantation (LT) in an 8-month-old boy with OI and cholestatic biliary cirrhosis. After 4 cycles of intravenous pamidronate, LT was performed under intravenous anesthesia using a left lateral section from his mother without mechanical retractors. The operation time was 420 min and estimated blood loss was 520 mL requiring one unit of RBC transfusion. He was discharged without surgical complications. Therefore, LT should be considered for patients with end stage liver disease and OI under organic multidisciplinary cooperation.

Public awareness about the specialty of anesthesiology and the role of anesthesiologists: a national survey.

BACKGROUND: The aims of this national survey were to determine the views of Korean people regarding the specialty of anesthesiology and the role of anesthesiologists and to consider the ways in which individual anesthesiologists and the Korean Society of Anesthesiologists inform the public. METHODS: This off-line national survey was conducted by a professional research organization to obtain exact and reliable data. The questionnaire included structured questions to identify perceptions of the specialty of anesthesiology and the role of anesthesiologists inside and outside the operating room, people's desire for explanation of anesthesia by anesthesiologists, and their opinion about the best way to raise awareness about anesthesia and anesthesiologists. RESULTS: Of the respondents, 25.2% did not know that anesthesiologists are in charge of anesthesia during surgery. Furthermore, even respondents who knew that had very little knowledge of anesthesiologists' actual roles inside and outside the operating room. Respondents wanted their anesthesiologist to inform them about their anesthesia. CONCLUSIONS: The public's awareness regarding the role of anesthesiologists seems to be inadequate. To improve this awareness, in hospitals, each anesthesiologist should provide patients with more exact and detailed information. Simultaneously, the National Society of Anesthesiology should provide systematic information reflecting the public's thoughts.

Torsade de pointes in liver transplantation recipient after induction of general anesthesia: a case report.

Torsade de pointes (TdP) is an uncommon and specific form of polymorphic ventricular tachycardia, associated with a prolonged QT interval. Prolongation of the QT interval is the most widely recognized electrophysiological abnormality in patients with liver cirrhosis. We observed a case of TdP leading to cardiopulmonary resuscitation after the induction of general anesthesia, in a patient with liver cirrhosis scheduled for emergency cadaveric donor liver transplantation. The patient had mild QT prolongation on preoperative electrocardiography with a corrected QT (QTc) interval of 455 ms. Drugs used in the preoperative period can elongate cardiac repolarization. Sevoflurane and 5-hydroxytryptamine type 3 receptor antagonists such as palonsetron, used during general anesthesia may have triggered further QT prolongation, producing a fatal condition such as TdP. More caution and consideration in selecting drugs for anesthetic management are necessary for liver cirrhosis patients, especially in patients with preoperative QT prolongation.

External validation of the Acute Physiology and Chronic Health Evaluation II in Korean intensive care units.

PURPOSE: This study was designed to validate the usefulness of the Acute Physiology and Chronic Health Evaluation (APACHE) II for predicting hospital mortality of critically ill Korean patients. MATERIALS AND METHODS: We analyzed data on 826 patients who had been admitted to nine intensive care units and were included in the Fever and Antipyretics in Critical Illness Evaluation study cohort. RESULTS: Among the patients enrolled, 62% (512/826) were medical and 38% (314/826) were surgical patients. The median APACHE II score was 17 (11 to 23 interquartile range), and the hospital mortality rate was 19.5%. Age, underlying diseases, medical patients, mechanical ventilation, and renal replacement therapy were independently associated with hospital mortality. The calibration of APACHE II was poor (H=57.54, p<0.0001; C=55.99, p<0.0001), and the discrimination was modest [area under the receiver operating characteristic (aROC)=0.729]. Calibration was poor for both medical and surgical patients (H=63.56, p<0.0001; C=73.83, p<0.0001, and H=33.92, p<0.0001; C=33.34, p=0.0001, respectively), while discrimination was poor for medical patients (aROC=0.651) and modest for surgical patients (aROC=0.704). At the predicted risk of 50%, APACHE II had a sensitivity of 36.6% and a specificity of 87.4% for hospital mortality. CONCLUSION: For Koreans, the APACHE II exhibits poor calibration and modest discrimination for hospital mortality. Therefore, a new model is needed to accurately predict mortality in critically ill Korean patients.

The effects of an insulin-glucose-potassium (IGK) pretreatment on the bupivacaine cardiotoxicity.

BACKGROUND: The purpose of this study is to evaluate the effect of an IGK pretreatment on the cardiotoxicity of bupivacaine. METHODS: Twenty-one anesthetized mongrel dogs were randomly divided into the following three groups: the control group (CG, n = 7), the treatment group (TG, n = 7) and the pretreatment group (PTG, n = 7). For the 30 min of pretreatment period, CG and TG received normal saline, while PTG received an IV bolus of insulin 2 U/kg, followed by an IGK infusion (2 U/kg/hr of insulin, 0.5-1.5 g/kg/hr of glucose, 1-2 mEq/kg/hr of KCl). The bupivacaine infusion was started at the rate of 0.5 mg/kg/min in all groups after the pretreatment period. CG received normal saline only. In TG, insulin (2 U/kg) was injected simultaneously with bupivacaine infusion, followed by the IGK infusion as with PTG. The hemodynamic variables and the time duration to reach the mean arterial pressure (MAP) of 60 mmHg were compared. RESULTS: The bupivacaine infusion decreased the cardiac index, MAP, and heart rate in all three groups. Although insulin concentration was higher in TG than in PTG during bupivacaine infusion, the hemodynamic variables in PTG decreased at the slowest rate. The time taken to reach MAP of 60 mmHg in PTG, TG, and CG was 51.4 ± 8.5, 36.4 ± 9.6, and 27.1 ± 8.7 min, respectively (P < 0.05). CONCLUSIONS: IGK delays the bupivacaine-induced cardiac depression. However, a pretreatment with IGK is more effective in delaying the bupivacaine-induced hypotension than simultaneous administration, regardless of insulin concentration.

Insulin/glucose infusion successfully resuscitates bupivacaine-induced sudden-onset circulatory collapse in dogs.

PURPOSE: In previous studies, insulin reversed the cardiac toxicity gradually induced by a continuous infusion of bupivacaine. In this randomized controlled study, we intended to simulate a more relevant clinical situation by injecting bupivacaine rapidly as a bolus to induce sudden-onset circulatory collapse in dogs. We then evaluated the insulin effect. METHODS: Bupivacaine (10 mg.kg(-1) iv) was rapidly administered intravenously to 12 dogs. At the onset of circulatory collapse (defined as a mean arterial pressure [MAP] of 30 mmHg), external chest compression was initiated. Insulin (2 U.kg(-1) iv) was given to the insulin-glucose (IG) group (n = 6) and the same volume of 0.9% saline was given to the control (C) group (n = 6). The primary outcome was successful resuscitation defined as both MAP ≥ 60 mmHg and sinus rhythm on an electrocardiogram that lasted ≥ 60 sec. Hemodynamic and blood variables were measured, including cardiac output and electrocardiogram intervals. RESULTS: All IG dogs were successfully resuscitated within 15 (3) min, whereas none of the control dogs were resuscitated (P = 0.002). After circulatory collapse, the average MAP was higher in group IG than in group C (P = 0.006). CONCLUSION: Insulin effectively reversed the sudden-onset circulatory collapse in dogs caused by an intravenous bolus injection of bupivacaine.